Collections · interview question
In an e-commerce catalog system, you want to store categories in a way that offers fast retrieval of a list of subcategories. What would be a suitable collection choice?
Multiple choiceHardchapter-4-curatedpremiumcollectionscollection-performance-basics
Answer and explanation
Correct answer
D. HashMap<String, List<String>>
Why
A HashMap allows you to associate a category with a list of subcategories, providing O(1) average time complexity for retrieval by key, which is efficient for this use case.
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